Universal Mobile Telecommunications Systems (UMTS) and High-Speed Packet Access (HSPA)
The Universal Mobile Telecommunications System (UMTS) is a third generation wireless telecommunication system and follows in the footsteps of GSM and GPRS. Since GSM was standardized in the 1980s, huge progress has been made in many areas of telecommunication. This allowed system designers at the end of the 1990s to design a new system that went far beyond the capabilities of GSM and GPRS. UMTS combines the properties of the circuit-switched voice network with the properties of the packet-switched data network and offers a multitude of new possibilities compared to the earlier systems. UMTS was not defined from scratch and reuses a lot of GSM and GPRS. Therefore, this chapter first gives an overview of the advantages and enhancements of UMTS compared to its predecessors, which have been described in the previous chapters. After an end-to-end system overview, the focus of the chapter is then on the functionality of the UMTS radio access network. New concepts like the Radio Resource Control (RRC) mechanisms as well as changes in mobility, call control and session management are also described in detail.
Over the years, the UMTS radio network system has been significantly enhanced and now offers broadband speeds far beyond the original design. These high-speed enhancements are referred to as High-Speed Packet Access (HSPA). An overview of the various enhancements over time is given in ...